Clean mackerels, remove head and fins. Cut into 6–8 cm pieces.
Grate carrots and dice onions into small cubes.
Heat olive oil in a pan, add onions and carrots, sauté briefly with a splash of water.
Transfer mackerel pieces to a pot. Add the softened carrots and onions on top. Pour in enough water to cover the bottom of the pot (do not fully submerge the fish).
Add salt, black pepper and chmeli-suneli (or your preferred seasoning blend).
Cover the pot and simmer on low heat for about 30 minutes, until the fish is tender and vegetables are fully cooked.
Serve warm with fresh herbs, a side of vegetables, potatoes or whole grains.